Auroral events are the prominent manifestation of solar/stellar forcing on planetary atmospheres and are closely related to the energy deposition by and evolution of planetary atmospheres. Observations of auroras are widely used to analyze the composition, structure, and chemistry of the atmosphere under study, as well as charged particle and energy fluxes that affect the atmosphere. Numerical kinetic Monte Carlo models had been developed allowing us to study the processes of precipitation of high-energy electrons, protons and hydrogen atoms into the planetary atmospheres on molecular level of description, taking into account the stochastic nature of collisional scattering at high kinetic energies. Such models are used to study auroras at both magnetized and non-magnetized planets in the Solar and extrasolar planetary systems. The current status of the kinetic model is illustrated in application to the auroral events at Mars.

This communication introduces two cases of the use of astronomy as a motivating context to interdisciplinary science education with emphasis on modeling activities. Firstly, a dedicated software, called SalsaJ, allows students to reproduce the same data analysis as made by astronomers. The case of exoplanet detection will be used as an exemple. Secondly, bodies of learners are considered to model movements of planets with a Human Orrery (a Spatio-Temporal Map of the Solar System), connecting thus mathematics, physics, geography and arts.

Recent GAIA observations revealed that the K-type star Gliese 710 will cross the Oort cloud in a distance between approximately 4000 and 12000 au in about 1.3 Myrs. This occurrence motivated us to study the influence of a stellar encounter on comets in the outer region of the solar system. Even if the Oort cloud extends to 100000 au from the sun, we restrict our study to the region between 30 and 25000 au where 25 million objects are distributed randomly. Comets at larger distances are not taken into account as they hardly enter the observable region after a single stellar fly-by. An overview of all objects that are scattered towards the sun for the different fly-by distances at 4000, 8000 and 12000 au shows that only a handful of objects are moving towards the sun immediately after the stellar encounter.

However, a subsequent long-term study of all objects that are moved into highly eccentric motion by the stellar fly-by shows a significant increase of comets crossing Jupiter’s orbit and entering into the observable region. In addition, our study shows the first comets crossing the orbit of Earth only about 2.5 Myrs after the stellar fly-by. Thus, the impact risk for the Earth increases only some million years after the stellar fly-by.

Based on observations by Bailer-Jones et al. (2018) who propose a close fly-by of the K-type star Gliese 710 in approximately 1.36 Myr we investigate the immediate influence of the stellar passage on trajectories of Oort cloud objects. Using a newly developed GPU-based N-body code (Zimmermann (2021)) we study the motion of 3.6 million testparticles in the outer Solar system where the comets are distributed in three different “layers” around the Sun and the 4 giant planets. We study the immediate influence of Gliese 710 at three passage distances of 12000, 4300, and 1200 au. Additionally, different inclinations of the approaching star are considered. Depending on the passage distance a small number of comets (mainly from the disk and flared disk) is scattered into the observable region (< 5 au) around the Sun. In addition, a huge number of comets (mainly the ones directly in the path of the passing star) shows significant changes of their perihelia. But, they will enter the inner Solar system a long time after the stellar fly-by depending on their dynamical evolution.

Perturbative analyses of planetary resonances commonly predict singularities and/or divergences of resonance widths at very low and very high eccentricities. We have recently re-examined the nature of these divergences using non-perturbative numerical analyses, making use of Poincaré sections but from a different perspective relative to previous implementations of this method. This perspective reveals fine structure of resonances which otherwise remains hidden in conventional approaches, including analytical, semi-analytical and numerical-averaging approaches based on the critical resonant angle. At low eccentricity, first order resonances do not have diverging widths but have two asymmetric branches leading away from the nominal resonance location. A sequence of structures called “low-eccentricity resonant bridges” connecting neighboring resonances is revealed. At planet-grazing eccentricity, the true resonance width is non-divergent. At higher eccentricities, the new results reveal hitherto unknown resonant structures and show that these parameter regions have a loss of some – though not necessarily entire – resonance libration zones to chaos. The chaos at high eccentricities was previously attributed to the overlap of neighboring resonances. The new results reveal the additional role of bifurcations and co-existence of phase-shifted resonance zones at higher eccentricities. By employing a geometric point of view, we relate the high eccentricity phase space structures and their transitions to the shapes of resonant orbits in the rotating frame. We outline some directions for future research to advance understanding of the dynamics of mean motion resonances.

It is shown that spatial ordering of the Solar planetary system can be described by simple wave algorithms. It is detected that the dependence “mean density – global period” reflects the ordering of this system and has signs of an evolutionary diagram.

We have analyzed the data on yearly mean international sunspot number (RZ) during the period 1610 – 2015 and orbital positions (ecliptic longitudes) of the giant planets in each 10-day interval during the period 1600 – 2099. We determined mean absolute difference ($\overline{\psi _D}$) of the orbital positions of the giant planets in each interval. We find that there exits a good correlation between cycle amplitude (RM, i.e. the maximum value of RZ) and the value of $\overline{\psi _D}$ at cycle maximum, suggesting that on longer time scales low/high solar activity associated with less/large spread in orbital positions of the giant planets (i.e. with a low/high value of $\overline{\psi _D}$).

At large distance scales, space exploration in the last decades has significantly helped in better locating the boundaries of the Heliosphere and outlining its shape as well as in probing the various plasma domains that separate the inner heliospheric region from the interstellar one. At shorter distance scales, a fleet of spacecraft has been probing the outer and inner Solar System plasma with a high level of detail.

This monitoring, complemented by space- and ground-based observations of processes relevant to the Heliosphere, has pointed out a series both of intrinsic and extrinsic perturbations that characterise the physical state of heliospheric plasmas both at small and large spatial scales and on short and long temporal scales.

By means of concept maps that schematise the association among concepts, in this work we will present a new domain ontology for the definition and characterisation of Heliospheric Weather and Climate.

Early Warning of Space Weather phenomena is one of the most important products produced by Mexican Space Weather Service (SCiESMEX). The aim is to deliver a verified warning to Mexican National Center for Disaster Prevention (CENAPRED) as well as to general public in near-real time automatically. First, the international pubic warning (or alert) is produced by Space Weather Prediction Center of National Oceanic and Atmospheric Administration, U.S.A. Further, the alert is received by SCiESMEX system, decodified, translated in Spanish and put in the context of local current conditions. The alerts are transformed and validated in agreement to Mexican policies of civil protection and CENAPRED protocols. The automatic system segments the information and delivers the corresponding web- page-alerts, emails, twits, facebook messages and SMS. The latency of the alert is 5 minutes. The code is running since January of 2015 without major interruptions.

Stellar occultations by solar system objects allow kilometric accuracy, permit the detection of tenuous atmospheres (at nbar level), and the discovery of rings. The main limitation was the prediction accuracy, typically 40 mas, corresponding to about 1,000 km projected at the body. This lead to large time dedicated to astrometry, tedious logistical issues, and more often than not, mere miss of the event. The Gaia catalog, with sub-mas accuracy, hugely improves both the star positions, resulting in achievable accuracies of about 1 mas for the shadow track on Earth. This permits much more carefully planned campaigns, with success rate approaching 100%, weather permitting. Scientific perspectives are presented, e.g. central flashes caused by Plutos atmosphere revealing hazes and winds near its surface, grazing occultations showing topographic features, occultations by Chariklos rings unveiling dynamical features such as proper mode “breathing”.

A Danish computer, GIER, from 1961 played a vital role in the development of a new method for astrometric measurement. This method, photon counting astrometry, ultimately led to two satellites with a significant role in the modern revolution of astronomy. A GIER was installed at the Hamburg Observatory in 1964 where it was used to implement the entirely new method for the measurement of stellar positions by means of a meridian circle, at that time the fundamental instrument of astrometry. An expedition to Perth in Western Australia with the instrument and the computer was a success. This method was also implemented in space in the first ever astrometric satellite Hipparcos launched by ESA in 1989. The Hipparcos results published in 1997 revolutionized astrometry with an impact in all branches of astronomy from the solar system and stellar structure to cosmic distances and the dynamics of the Milky Way. In turn, the results paved the way for a successor, the one million times more powerful Gaia astrometry satellite launched by ESA in 2013. Preparations for a Gaia successor in twenty years are making progress.

We compute the spherical albedo for a Lommel-Seeliger scattering ellipsoidal asteroid with a realistic disk-integrated phase function. The spherical (or Bond) albedo gives the ratio of the fluxes incident on and scattered by an asteroid. Thus, it plays a key role in the determination of the flux absorbed and afterwards thermally emitted by the asteroid at longer wavelengths. We provide extensive computations for the spherical albedo of low-albedo and moderate-albedo asteroids by utilizing the analytical disk-integrated brightness of a Lommel-Seeliger ellipsoid. In doing so, we utilize realistic triaxial models of known asteroids as well as idealistic prolate or oblate models of substantial elongation or flatness, respectively. We show that the spherical albedos can vary significantly as a function of the rotational pole orientation, rotational phase, and the triaxial ellipsoidal shape: variations of the order of 5-10% are realistic, with a tendency to grow with increasing elongation or flatness of the shape.

Studies for spin parameters and shapes of asteroids provide us with important information about the interior structure of asteroids and the physical processes they have undergone. A large sample of basic physical parameters can help us also understand the evolution of asteroids. There is scarce information for slowly-rotating larger asteroids because more effort is required for observing them. Because of this, we have established an international collaboration to study slowly-rotating asteroids. As the first step of this project, we have observed asteroids (168) Sibylla and (346) Hermentaria in 2014 and 2015 using several telescopes located in China, Chile, and U.S.A. Combining previous photometric data with our new data, we have performed preliminary analyses and obtained spin parameters and shapes with their uncertainties for these two slowly-rotating asteroids for the first time, using the convex inversion method and the virtual photometry Monte Carlo method. A pair of pole solutions for (168) Sibylla are found around (4.3°, 53.5°) and (183.5°, 52.6°) with a period of 47.0000 h. We have found that the shape of Sibylla resembles an oblate spheroid. For (346) Hermentaria, we have also found a pair of pole solutions around (134.5°, 16.7°) and (321.5°, 14.5°) with comparable rms-values with a spin period of about 17.79000 h, and a shape resembling a prolate spheroid.

Comets are probably the best archives of the nascent solar system, 4.5 Gyr ago, and their compositions reveal crucial clues on the structure and dynamics of the early protoplanetary disk. Anhydrous minerals (olivine and pyroxene) have been identified in cometary dust for a few decades. Surprisingly, samples from comet Wild2 returned by the Stardust mission in 2006 also contain high temperature mineral assemblages like chondrules and refractory inclusions, which are typical components of primitive meteorites (carbonaceous chondrites - CCs). A few Stardust samples have also preserved some organic matter of comet Wild 2 that share some similarities with CCs. Interplanetary dust falling on Earth originate from comets and asteroids in proportions to be further constrained. These cosmic dust particles mostly show similarities with CCs, which in turn only represent a few percent of meteorites recovered on Earth. At least two (rare) families of cosmic dust particles have shown strong evidences for a cometary origin: the chondritic porous interplanetary dust particles (CP-IDPs) collected in the terrestrial stratosphere by NASA, and the ultracarbonaceous Antarctic Micrometeorites (UCAMMs) collected from polar snow and ice by French and Japanese teams. Analyses of dust particles from the Jupiter family comet 67P/Churyumov-Gerasimenko by the dust analyzers on Rosetta orbiter (COSIMA, GIADA, MIDAS) suggest a relationship to interplanetary dust/micrometeorites. A growing number of evidences highlights the existence of a continuum between asteroids and comets, already in the early history of the solar system.

By proclaiming the IYL2015, the United Nations recognized the importance of light and light based technology in the lives of the citizens of the world and for the development of global society on many levels. Light and application of light science and technology are vital for existing and future advances in many scientific areas and culture. Light is a key element in astronomy: as astronomers, it is what we study and makes our science possible, but it is also what threatens our observations when it is set-off from the ground (light pollution). The UN-designated year 2015 represented a magnificent and unique opportunity for the global astronomical community to disseminate these messages and raise the awareness of the importance and preservation of dark skies for heritage and the natural environment.

As such, the International Year of Light served as a launching pad for several projects during 2015. Two other projects with equally as impressive programs are highlighted and begin the narrative for this section on public education and outreach programs on light pollution issues and solutions.

We update the list of candidates to be considered by the IAU as dwarf planets using the criterium suggested by Tancredi & Favre (2008). We add here the information collected in the last 10 years (mostly the sizes and albedos by the herschel hey program TNOs Are Cool). We compare the physical characteristics of these candidates with the physical characteristics of the rest of the TNOs. Our goal is to study if there are common physical properties among the candidates that enable the identification of a dwarf planet.

We use radar images with decameter resolution to measure the sizes, shapes, spin states, mutual orbits, masses, and densities of components of asteroid binaries and triples. We simulate the spin-orbit dynamics of these systems and map the possible spin configurations of the satellites on surface of section plots. The presence of chaotic regions in the phase space has important consequences for the evolution of binary asteroids. It may substantially increase spin synchronization timescales, delay BYORP-type evolution, and extend the lifetime of binaries.

We investigate the outcome of collisions of Ceres-sized planetesimals composed of a rocky core and a shell of water ice. These collisions are not only relevant for explaining the formation of planetary embryos in early planetary systems, but also provide insight into the formation of asteroid families and possible water transport via colliding small bodies. Earlier studies show characteristic collision velocities exceeding the bodies' mutual escape velocity which—along with the distribution of the impact angles—cover the collision outcome regimes ‘partial accretion’, ‘erosion’, and ‘hit-and-run’ leading to different expected fragmentation scenarios. Existing collision simulations use bodies composed of strengthless material; we study the distribution of fragments and their water contents considering the full elasto-plastic continuum mechanics equations also including brittle failure and fragmentation.

Since 1992, 60 large Kuiper Belt objects have been detected by ground-based telescopes. Previous surveys which have detected objects have searched approximately 60□° and detected objects with magnitudes 20·6 < mR < 25·0. However, the luminosity function of brighter Kuiper Belt objects is not well determined. The detection of brighter objects would improve our ability to determine the Kuiper Belt objects' surface composition and provide constraints on the population statistics of different formation mechanisms. This paper describes a survey of 12·0□° of sky near the ecliptic to a limiting magnitude of mR ∼ 21. A slow moving candidate was detected near the magnitude limit of the survey.

The largest uncertainty in the ephemerides for the inner planets is in the orientation of the dynamical system to the celestial reference frame. A program of VLBI measurements of spacecraft in orbit about Venus and Mars has been performed to reduce the orientation uncertainty to 0.2 milliarcseconds.